It’s an in-depth explanation of rainbows and the physics that create them, much of which contradicts the layperson’s understanding of them. How is the title clickbait if it’s accurate to the content?
Clearly any video that asks a question or implies a strange phenomenon or situation is click bait. See also:chubbyemu videos here
For the record, I do not think these are click bait, if they're accurate. Or, at least, they're click bait that actually gives you a worm instead of some shitty rubber faux worm.